BEIJING (Reuters) - China is repeatedly postponing discussions with Western governments on the possibility that Liu Xia, the widow of Nobel Peace Prize-winning dissident Liu Xiaobo, be allowed to leave the country, according to a source with direct knowledge of the case.

Liu Xia, a poet and artist who suffers from depression, has effectively been under house arrest since her husband won the prize in 2010. Liu Xiaobo died in Chinese custody in July last year after being denied permission to go abroad for treatment of advanced liver cancer.

Since his death, Liu Xia has continued to be closely monitored by government minders and is unable to travel or to speak freely with friends and family, other than in infrequent pre-arranged phone calls and visits, according to friends and Beijing-based Western diplomats.

Now, fears are mounting that no progress has been made towards allowing her to travel outside the country despite the conclusion of the annual meeting of parliament, which Chinese authorities previously said was the reason for delays.

“There are growing doubts that she will be released in the near future,” a Western diplomat involved in the case told Reuters.

“The case has so far been handled discreetly in the expectation that she would soon be permitted to leave the country,” the diplomat said.

China's foreign ministry was unable to immediately comment on the case. China's State Council Information Office, which comments on behalf of the Communist Party, did not reply to a faxed request for comment.

WANTS TO LEAVE CHINA

Liu has told diplomats and friends on numerous occasions that she wants to leave China. Friends of the couple say that allowing her the freedom to do so was one reason for her husband’s insistence on his deathbed that he be treated overseas.

Chinese dissidents have in the past been allowed to leave the country and take up residence in a willing Western host nation.

However, since coming to power in 2013, Chinese President Xi Jinping has presided over a sweeping campaign to quash dissent throughout Chinese society, detaining hundreds of rights activists and lawyers; dozens have been jailed.

China has said that Liu Xia, as a private citizen, is free to do as she pleases and that the details of the case remain an internal affair of China’s.

Friends of Liu Xia say that the process has been slowed by Chinese government fears of what she might say once free, as well as her insistence that her brother, Liu Hui, also be allowed to leave.

He was handed an 11-year jail sentence for fraud in 2013 and was later released under house arrest, where he remains closely monitored, according to friends of the family.

"The Chinese authorities are primarily concerned that after she leaves she will openly tell the international community about her and Liu Xiaobo's plight," Ye Du, a writer and close friend of the couple, told Reuters.

"The authorities have seized upon her weakest point, which is her and Liu Hui's total dependence on one another, so they may agree to her leaving, but only if Liu Hui stays as a hostage," he said in reference to the pressure that the Chinese authorities can put on the China-based relatives of dissidents overseas.

Liu Xia continued to write and paint after Liu Xiaobo's imprisonment but has told friends that she constantly struggles with loneliness and depression and has become dependent on alcohol, cigarettes and medication.

The repeat delays also reflect a failure by foreign governments and international organizations to come together and "raise the cost" of not allowing her to leave by pushing the case publicly and repeatedly, according to Sophie Richardson, Washington-based China director for Human Rights Watch.

"From Beijing's prospective, there's no place to go but down in releasing her," Richardson said. "It's not a complicated diplomatic thing. It's about making it more painful for Beijing to keep her than release her."